Position sensor for determining the position of a moving object

Abstract

A position sensor to determine the absolute position of an object features a rotary position sensor with a tooth gear, which is resiliently and elastically tensioned against a toothing on the moving object.

What is claimed is:  
     
       1. Position sensor to determine the position of a moving object, wherein a rotary position sensor is coupled by means of a toothed gear to a toothing on the moving object, the toothed gear and the toothing of the moving object being under mutual elastic tension, wherein the moving object is a rotary shaft and the toothing is a driven toothed gear connected to the shaft, and two rotary position sensors are coupled via driven toothed gears to the driving toothed gear, wherein the rotary position sensors are seated in bearing elements and the bearing elements are pressed by means of resilient, elastic tension bars in the direction of the shaft. 
     
     
       2. Position sensor according to  claim 1  wherein the axes of rotation of the rotary position sensors and of the shaft are located in a common plane. 
     
     
       3. Position sensor according to  claim 1  wherein the rotary position sensors are seated on a common bearing element and the bearing element is connected by means of resilient, elastic tension bars to an additional bearing element which is braced by means of an additional driven toothed gear against the driving toothed gear. 
     
     
       4. Position sensor according to  claim 3  wherein all driven toothed gears are pretensioned in the direction of the midpoint of the driving toothed gear. 
     
     
       5. Position sensor according to  claim 4  wherein the driven toothed gears are fixed in position with respect to the driving toothed gear by means of a torsion stop in such a manner that its axis of rotation is held in place in the circumferential direction of the driving toothed gear and can only move radially relative to the midpoint of the driving toothed gear. 
     
     
       6. Position sensor according to  claim 5  wherein the driven toothed gears, the bearing elements and the tension bars are designed as one structural unit which can be displaced linearly along a retaining plate. 
     
     
       7. Position sensor according to  claim 6  wherein an error signal (ε) for the new part is ascertained at a factory which is proportional to the measured error the the position sensor, the error signal (ε) and a preset limit value are stored, and, during subsequent operation, a current error signal (ε actual ) is determined, and a check is run to determine whether the two error signals (ε, ε actual ) differ by more than the stored limit value, whereupon a warning signal is generated. 
     
     
       8. Position sensor according to  claim 7  wherein the factory-ascertained error signal (ε), is determined only for a preset rotary position, and the check of the current error signal (ε actual ) likewise occurs only for the preset rotary position.